Show HN: Chawan TUI web browser | Hacker News Reader

Show HN: Chawan TUI web browser

chawan.net

387 pointsshiomiru69 comments

A terminal-based web browser in Nim.[1] Has acceptable (YMMV) CSS rendering, some JS support, and inline images (sixel/kitty). It can also use various protocols other than http(s) such as (s)ftp, gopher, gemini, ...

Chawan started out as a w3m clone, and the UI still resembles it. However, the architecture has turned out quite different, with pages loaded in separate processes, and protocol/file type handling separated out into external binaries. An interesting result is that you can even register decoders for custom inline image formats, although practical use cases of this are rather minimal.

There is a gallery showcasing some websites being rendered here: https://chawan.net/gallery/index.html

[1]: https://nim-lang.org

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Thanks, always appreciate ways of not using another blink engine for a brief research side quest! looking forward to test after school ; )

As it hasn't been brought up yet, a really great hack (esp. for us without sixel) is this terminal port of chromium: https://github.com/fathyb/carbonyl .. but the original creator hasn't had time to get back to it. So it is very bare bones & lacks a lot of features, like keyboard shortcuts, file saving.. but obviously it brings full web compatibility and is just very cool. Wishing for someone with rust skills to pick it up again, last time I looked (couple of months ago) none of the forks had any momentum.

Side note but on the carbonyl github post, everyone keeps asking about the author's health as if he's safe or not, given he is palestinian.

I hope the author is safe. His work was really good,I must say. Fuck wars in general.

Well his github profile says he's in France, so let's hope he's kinda safe.. But yeah, fuck wars in general. Also, fuck the generals.. and their commanders. Oh, and the whole military-industrial complex as well. We urgently need a transition towards a planetary non-commercial commons-based economy..

@shiomiru

What's the best resource (paid or free) in your opinion for learning about these TTY related concepts?

I'm aware of https://www.linusakesson.net/programming/tty/index.php for example, but that doesn't go into termcap/terminfo/curses.

one of the comments mentions http://www.amazon.com/termcap-terminfo-OReilly-Nutshell-Lind... though (online https://www.scribd.com/document/831486848/Termcap-and-Termin...)

chawan has a custom terminal module, so my knowledge about the standard X/Open curses is not that great.

That said, for the actual escape sequences, XTerm's ctlseqs.ms[1] is an invaluable resource. I also took many ideas from nick black's notcurses[2], and I especially recommend his notes on "sprixels".[3]

[1]: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html

[2]: https://nick-black.com/dankwiki/index.php/Notcurses

[3]: https://nick-black.com/dankwiki/index.php/Theory_and_Practic...

This is beautifully done. I'm going to use this for some of my daily work and see how far I can get with it. HN looks exceptionally good. Thank you!

Good of you! Don't forget to file the bugs you find.

This is super cool! Bravo. Awesome to see it written in Nim too.

When I do `cha example.com` I can't figure out how to use any of the commands (hjkl, etc). The only keys I've found that have any effect are typing numbers which show up in the bottom left. Haven't figured out how to do anything with those. Am I missing something obvious about how to use this or could this be a bug?

I built from source on MacOS Sequoia 15.5 Apple Silicon using Nim 2.24. Pages load correctly, I just can't get the commands to work. Thanks!

I tried it in Ghostty, iTerm2, and Terminal.app and they all behaved the same.

It's a bug, thanks for reporting. I've created a ticket: https://todo.sr.ht/~bptato/chawan/63

Could you please pull the macos-input branch from https://git.sr.ht/~bptato/chawan and report back on what the `a` file includes after opening a site and typing some commands? (Should be created in the current working directory.)

Here's the contents of a. Let me know if there are any other commands you'd like me to type.

``` handleCommandInput 1, buffer "" c 'j' handleCommandInput 2, buffer "" c 'j' after handleCommandInput, buffer 0x104c5b780"j" c 'j' handleCommandInput 1, buffer "" c 'k' handleCommandInput 2, buffer "" c 'k' after handleCommandInput, buffer 0x104ca8b70"k" c 'k' handleCommandInput 1, buffer "" c 'l' handleCommandInput 2, buffer "" c 'l' after handleCommandInput, buffer 0x104c5bab0"l" c 'l' handleCommandInput 1, buffer "" c 'k' handleCommandInput 2, buffer "" c 'k' after handleCommandInput, buffer 0x104ca8d20"k" c 'k' handleCommandInput 1, buffer "" c 'j' handleCommandInput 2, buffer "" c 'j' after handleCommandInput, buffer 0x104c5b480"j" c 'j' handleCommandInput 1, buffer "" c 'h' handleCommandInput 2, buffer "" c 'h' after handleCommandInput, buffer 0x104ca89c0"h" c 'h' handleCommandInput 1, buffer "" c 'g' handleCommandInput 2, buffer "" c 'g' after handleCommandInput, buffer 0x104cae780"g" c 'g' handleCommandInput 1, buffer "" c '1' after handleCommandInput, buffer "" c '1' handleCommandInput 1, buffer "" c '2' after handleCommandInput, buffer "" c '2' handleCommandInput 1, buffer "" c '3' after handleCommandInput, buffer "" c '3' handleCommandInput 1, buffer "" c '1' after handleCommandInput, buffer "" c '1' handleCommandInput 1, buffer "" c '2' after handleCommandInput, buffer "" c '2' handleCommandInput 1, buffer "" c '2' after handleCommandInput, buffer "" c '2' handleCommandInput 1, buffer "" c '3' after handleCommandInput, buffer "" c '3' handleCommandInput 1, buffer "" c '\3' handleCommandInput 2, buffer "" c '\3' after handleCommandInput, buffer 0x104cae690"\3" c '\3' handleCommandInput 1, buffer "" c '\3' handleCommandInput 2, buffer "" c '\3' after handleCommandInput, buffer 0x104adaed0"\3" c '\3' handleCommandInput 1, buffer "" c '\3' handleCommandInput 2, buffer "" c '\3' after handleCommandInput, buffer 0x104ca8720"\3" c '\3' handleCommandInput 1, buffer "" c '\4' handleCommandInput 2, buffer "" c '\4' after handleCommandInput, buffer 0x104bf8d80"\4" c '\4' handleCommandInput 1, buffer "" c '\3' handleCommandInput 2, buffer "" c '\3' after handleCommandInput, buffer 0x104caaa80"\3" c '\3' handleCommandInput 1, buffer "" c '\4' handleCommandInput 2, buffer "" c '\4' after handleCommandInput, buffer 0x104ca8e40"\4" c '\4' ```

Strange, so it sees your input but still doesn't evaluate the commands...

OK, let's try something else. On master, is anything written to the status line if you press `p` when started with

    cha -o'page.p="pager.alert(config.page.j)"' -V

I'm on Mac OS, encountering the same problem. I tried opening `cha -o'page.p="pager.alert(config.page.j)"' -V` then press `p`...nothing happens

Nothing happens for me either

Fixed on master.

(It turned out to be a miscompilation on part of clang; quite interesting, see the ticket linked above for details.)

Very nice! I compiled this from source on my Lenovo M8 4h gen running termux: I only had to install nim. It even installed nicely despite there being no "root" user.

I rabbit-holed a little and apparently Chrome and Safari no longer even fully pass Acid2 and Acid3?

Here is a relevant discussion: https://news.ycombinator.com/item?id=15256890

I've always tried to make my websites look good in Links and now it looks like I have a new candidate.

Having support for some CSS makes it a bit more difficult, as spacing between elements is now an issue, where previously links would ignore margins and padding all together which were used to display cleaner inline list elements (for menus and such).

The intention is that it should "just work"... I'm aware sometimes it doesn't, you can consider that a bug :)

But if you really want custom CSS for grid displays, chawan does support the standard "grid" media feature: https://developer.mozilla.org/en-US/docs/Web/CSS/@media/grid

I have implemented changes based on your advice of using @media: grid, and everything looks better now. You can check it here: https://brutalinks.tech (it's a link aggregator similar to HN).

I had no idea this CSS API existed. I'll add that to my CSS, thank you! :)

I'll check if the issue tracker has anything related to supporting titled alternate stylesheets (and eventually allowing users to pick one of them), because on the website where I made efforts for the markup to look reasonable on links, I also have a "simple" style that removes most of the CSS fanciness.

Long time w3m user here. Tried it and I can love it. Very nice.

Is that your design choice not having "Open URL"(Address bar) feature?

The address bar should open by pressing C-l (control + L).

Wonderful! Thanks!

I see you don't use termcap/ncurses anymore. Do you perform terminal handling yourself directly?

Thanks again!

Chawan never really used ncurses, only termcap. (ncurses just happens to implement termcap too.)

I started with termcap because I was already familiar with it through w3m. But termcap is an obsolete interface, and cannot describe the only useful attribute for modern terminals (true color). Its only benefit was "maybe it accidentally works on a hardware terminal from the 80s", which is cool but not really worth the extra failure mode.

So instead of migrating to terminfo, I ditched it completely in favor of terminal queries (which were already necessary for other reasons). There is still a built-in terminal database, to detect known TERM values with XTerm incompatibilities. But a terminal that correctly responds to queries will work out of the box, even if its TERM value is unknown.

> I started with termcap because I was already familiar with it through w3m. But termcap is an obsolete interface, and cannot describe the only useful attribute for modern terminals (true color). Its only benefit was "maybe it accidentally works on a hardware terminal from the 80s", which is cool but not really worth the extra failure mode.

Priorities, I guess. As long as I'm in a terminal, I'd rather have support for hardware terminals from the 80s than truecolor. But my only hardware terminal is a VT-420, so probably works for more or less anything that supports base XTerm (monochrome).

My jaw dropped when HN loaded first try from Termux! Nice work!

Thanks :)

If you're interested, I posted a user style for HN here: https://lists.sr.ht/~bptato/chawan-devel/%3CD9S40OS2QWHL.PXQ...

Mainly just to fix the vote arrows, because for now background-image only renders placeholders.

This is really impressive! Do you a have roadmap for upcoming or planned features?

The closest thing is https://codeberg.org/bptato/chawan/raw/branch/master/todo, but it's somewhat outdated and I rarely bother to sort it according to priority...

Finally a good tool to view HN in terminal. Thank you! Where can I find the keyboard shortcuts? I can move with vim key binding, but can go back.

cha-config(5) or about:chawan. The former also has an online version: https://chawan.net/doc/cha/config.html#pager-actions

For navigation in particular you'd use capital D to discard the current buffer and return to the previous page. There's also , (comma, back) and . (period, forward), which non-destructively cycle through the stack.

(Well, it's really a tree, but the UI mostly treats it as a stack.)

Thank you so much!

always nice to see something written in nim. In my very novice eyes, it is the most interesting language that is situated between C/C++ and python. It's a pity it never took off. The productivity of its users compared to the userbase size always made me think I'm right even if I'm far to be knowledgeable enough on the topic

Nim(rod) was released soon before Golang, and the overlap in features probably stopped the former one.

Can be easily built on macOS with just a single 'make'. Cool.

And nice to see there's a new elinks alternative.

I think making markdown browser would totally make sense for terminal and would work really well. Come to think about it, you can even, Netscape style even allow editing of the pages. Now that would be something.

Nim is wonderful language and I am glad to see it used for this.

glow is kinda that: https://github.com/charmbracelet/glow

Thanks, this is a good find

This works great, been playing with it through s-search and it works way better than w3m. =)

I recommend perusing the code. Since it’s in Nim it’s pretty approachable (and performant). There’s still lots of gnarly bits like implementing HTML DOM and web specs, but it doesn’t take you days to grasp the basic setup.

Gotta love Nim

Awesome and in Nim!

I love this browser, thank you for building it!

Glad you like it :)

How are those images rendered in text UI?

OK. Found it:

Displayed using Sixels or the Kitty protocol. Supported input formats are PNG, JPEG, BMP, GIF (stb_image), WebP (jebp) and SVG (nanosvg). Opt-in; edit the config to enable it.

Inline using sixel. Go look at the screenshots, it's not bad.

Yes, screenshots are nice. That's why I asked.

btw.

Rendering images or movies on the TTY is common.

fbida: https://www.kraxel.org/blog/linux/fbida/

mpv: https://mpv.io/

Fbida sometimes need the -d option pointing to /dev/drm/something, when using screen or tmux.

MPV required for years -vo=drm on the TTY but since some months it always works. Nice improvement :)

A display server is not needed.

It is first time I saw it today. Thanks!

GPM support?

No GPM yet, but it does recognize XTerm's mouse protocol.